0071643192.pdf

CARDIOVASCULAR EMERGENCIES

■ More likely to have DM and HTN, less likely to be smokers

■ Older than men at time of first MI

■ Worse prognosis because of delayed and less aggressive care

Cocaine-associated

■ Greatest risk within first hour after use

■ Arterial vasoconstriction, sympathetic stimulation, increased platelet

aggregation, accelerated atherosclerosis and thrombosis

■ Only one-third of cocaine-associated MI have significant CAD on cardiac

catheterization

■ Atypical symptoms: dyspnea, diaphoresis, nausea

■ ECG changes more atypical

■ 6% of all cocaine chest pain patients rule in by cardiac markers

■ Treat with O 2 , NTG, ASA, benzodiazepines. Beware of using β-blockers

(including labetalol) because of unopposed αadrenergic effects.

■ Complications are extremely rare if they do not present within 12 hours

of presentation.

A 67-year-old male with a history of hypertension, previous MI, and

known ejection fraction of 35% complains of worsening dyspnea over

2 days. On examination his BP =185/95 and he has bilateral rales, S3 gal-

lop,elevated jugular venous pressures, and bilateral pitting edema. ECG is with-

out acute ST- or T-wave changes. What is the best initial therapy for this patient?

Based on history and examination, this patient has acute decompensated

heart failure. Provide supplemental O 2 as needed. The mainstay of initial therapy

is afterload reduction with nitrates and diuretics.

HEART FAILURE

Heart failure is the inability of the myocardium to adequately meet the demands

of the body.

CAUSES

Common causes are listed in Table 2.10.

Systolic Versus Diastolic Dysfunction

Systolic dysfunction:

■ Usually from ischemic heart disease and myocardial cell death

■ Impaired contractility

■ Ejection fraction (EF) <40%

■ Output is dependent on resistance to emptying the ventricle (afterload).

Diastolic dysfunction:

■ Usually from chronic HTN and left ventricular hypertrophy

■ Impaired relaxation and ventricular filling

■ Normal ejection fraction

■ Output is dependent on filling of the ventricle (preload)

Other terms used to describe heart failure are based on clinical presentation:

■ Left-sided vs R-sided heart failure

■ High output heart failure

Ischemic heart disease is the

most common cause of heart

failure in the United States.

With diastolic dysfunction,

cardiac output is dependent

on ventricular filling

(preload).

With systolic dysfunction,

cardiac output is dependent

on resistance to emptying the

ventricle (afterload).